温州地区汉族人群G蛋白β3亚基C825T基因多态性与肥胖的相关性研究

Association of GNB3 gene C825T polymorphism to obesity in Han nationality of Wenzhou

目的研究温州地区汉族人群G蛋白β3亚基（GNB3）C825T等位基因多态性与超重及单纯性肥胖的相关性。方法超重及单纯性肥胖组为肥胖专科门诊中随机选取161例超重或单纯性肥胖患者，并于温州市中心血站随机选取313名体重正常健康献血者为对照组，PCR-RFLP检测基因型。结果（1）温州地区汉族人群GNB3 825T等位基因频率为0．428，与其他人种的基因频率显著不同。（2）超重及单纯性肥胖组的TT基因型携带者显著增加（P〈0．01），TT／CT导致肥胖的比数比（OR值）为2．9（95％可信区间1．8-4．7，P〈0．01）；TT／CC致肥胖的OR值为2．7（95％CI 1．5—4．7，P〈0．01）；TT基因型分布按体重指数（BMI，kg／m^2）分组后，正常体重（18≤BMI〈23）、超重（23≤BMI〈25）、Ⅰ度肥胖（25≤BMI〈30）和Ⅱ度肥胖（BMI≥30）4组均显著高于低体重（BMI〈18组，P〈0．05或P〈0．01）；Ⅰ度肥胖、Ⅱ度肥胖组高于正常体重组（均P〈0．05）；Ⅱ度肥胖组高于超重组（P〈0．01）。（3）同组男女间比较GNB3 C825T基因型和T等位基因频率分布差别无统计学意义。结论GNB3 C825T等位基因频率分布存在种族差异，温州地区汉族人群GNB3 825T等位基因频率为0．428，GNB3 825T等位基因与超重及单纯性肥胖呈正相关。GNB3 825T基因型可作为早期预测单纯性肥胖的遗传学指标之一。

Objective To determine the relationship between C825T polymorphism in G protein beta 3 subunit （GNB3） gene and overweight as well as simple obesity in Wenzhou Han nationality population. Methods This study included 161 patients with overweight or simple obesity and 313 normal controls. The patients were randomly recruited from Obesity Special Clinic and the controls from Wenzhou Central Blood Bank. Genotypo was determined by PCR-RFLP. Results （ 1 ） GNB3 825T allele frequency in Wenzhou Han nationality population was 0.428, which was significantly different from other ethnics; （2） TT genotype in overweight and simple obesity was significantly increased （ P 〈 0.01 ）. Odds Ratio （OR） （TT/CT） for overweight and simple obesity was2.9（1.8-4.7, P〈0.01）; OR （TT/CC） for overweight and simple obesity wes 2.7（1.5-4.7, P〈 0.01 ） ; When subdivided according to body mass index （ BMI）, the frequencies of TT genotype in normal weight （18≤BMI 〈23）, overweight （23≤BMI 〈25）, I degree obesity （25≤BMI 〈30）, Ⅱ degree obesity （BMI≥ 30） groups were significantly higher than that in low weight group （ P 〈 0.05 or P 〈 0.01 ）, the frequencies of TT genotype in I degree obesity and Ⅱ degree obesity groups were higher than that in normal weight group （ beth P 〈 0.01 ） which was significantly higher in Ⅱ degree obesity group than that in I degree obesity group （ P 〈 0.01 ）. （3） In the same group, there was no difference in the distributions of GNB3 C825T genotype and C/T allele frequency between male and female. Conclusion There exists ethnic difference in the distribution of GNB3 C825T allele frequency, with 0.428 in Wenzhou Han nationality population. GNB3 825T allele is positively associated with overweight and simple obesity. GNB3 825T genotype may be used as genetic marker in predicting the risk of developing simple obesity in Chinese of the Han nationality population.